Tim Sherwood is expected to depart White Hart Lane at the end of the season, cutting short his 18-month contract, with de Boer and Louis van Gaal among those heavily linked to the post.
With van Gaal now backed to replace David Moyes at Manchester United, de Boer has emerged as the favourite for the Spurs job and he revealed that an approach had been made earlier in the week.
The former Ajax, Barcelona and Rangers defender has won four consecutive Eredivisie titles in Holland since taking the job in 2010 and he says he is staying focused there for the time-being.
"It is very quiet here on my phone, and also for my agent. I am not busy with all that," de Boer told Dutch newspaper Algemeen Dagblad.
"My contract with Ajax runs until 2017, so until that time I will only think about Ajax or serious offers."
Asked whether he regretted being so open regarding Spurs' approach, de Boer replied: "No, why should I? I was interviewed by NOS and gave a honest answer.
"There were already rumours for a longer time. So I thought within a couple of seconds, I should speak with openness."